package 实现类.作业;

import java.util.Scanner;

public class zuoye2 {
    public static void main(String[] args) {
        Scanner input=new Scanner(System.in);
        System.out.print("请输入");
        String nums=input.next();
        StringBuffer str=new StringBuffer(nums);
        for (int i=str.length()-3;i>0;i=i-3){
            str.insert(i,',');

        }
        System.out.println(str);
    }
}
